Evaluation Of The Health And Phenotypic Variation Of Sophora Japonica L.in The Core Area Of Beijing

Accurately evaluate the health status and its influencing factors of Sophora japonica L.in Beijing’s capital functional core area,and to provide a theoretical basis for formulating S.japonica L.’s scientific management and protection technical measures;According to the variation characteristics of S.japonica L.phenotypic traits in Beijing,determine a strategy for directed screening of the best germplasm,and provide a resource base for selection of S.japonica L.fine varieties.In this study,the secondary tree health diagnosis method was used to evaluate each S.japonica L.tree in the core area,use principal component analysis to establish a health evaluation model,and analyze the important factors affecting the health of S.japonica L.;Sampling survey of the main phenotypic traits of S.japonica L.in Beijing,using common data statistics and calculation methods such as analysis of variance,principal component analysis,multiple comparisons,etc.,to analyze the main sources of phenotypic trait variation,and targeted selection of excellent S.japonica L.individual plants.The results show,healthy S.japonica L.plants accounted for 12.81%,sub-healthy individual plants accounted for 82.03%,and unhealthy individual plants accounted for 5.16%,the damage level of unhealthy plants is 29.51% at first level,36.97% at second level,23.66% at third level,and 9.86% at dying,the core area of S.japonica L.health score with its diameter at DBH and crown width increases the overall decline,health condition is better under organic material covering,pruning specifications,distance of 2 to 4 meters from the facility and without shading.The average coefficient of variation of the phenotypic traits of S.japonica L.is 25.08%,and the variation range of the coefficient of variation is 7.01%～264.44%,the order of the main sources of S.japonica L.phenotypic diversity is leaf size,leaf color,leaf shape,fruit fullness,crown,three types of fine germplasm of S.japonica L.were screened directionally,they were from two populations of XFDJ and ALXL in Chaoyang district.It can be concluded that,overall of the S.japonica L.in Beijing capital functional core area are healthy and sub-healthy,and have good conservation and conservation potential,but a part of unhealthy plants are severely damaged and need to be dealt with urgently,covering organic materials at the base of plants,standardizing pruning techniques,ensuring planting distance more than 2 meters from the facility and no shading are important measures for S.japonica L.conservation management to promote its healthy growth.The phenotypic traits of S.japonica L.germplasm resources in Beijing urban area are rich in phenotypic variation,and the degree of variation is high,the variation of leaf positions is the main source of phenotypic diversity,the best germplasm of S.japonica L.of 3 types with 10 copies of each was screened out,it can be used as an excellent propagation material for the further collection,preservation and genetic improvement of the germplasm resources of S.japonica L.